Alcohol - The Spirit of Christmas

Alcohol - The big picture.

So before we get accused of blanketing this issue we had better make it crystal clear what 'alcohol' is.

As a chemist I can tell you that an alcohol is any organic (carbon based) molecule that contains an -OH functional group. Ethanol fits that description but it is not the only one. As a cosmetic chemist I use lots of different chemicals with alcohol functionality to make cosmetics. These include many fatty alcohols that exist in nature in vegetable oils - Cetyl Alcohol, Stearyl Alcohol, Lanolin Alcohols, Behenyl Alcohol; alcohol based preservatives and fragrance additives - Benzyl Alcohol, Dichlorobenzyl Alcohol, Phenethyl Alcohol, Phenoxyethanol and alcohol based solvents: Ethanol, Isopropanol and even Glycerin or Sorbitol- sugar alcohols (or polyol as it has more than one -OH group) as humectants. In looking at the bigger picture, the alcohol family, it becomes clear why claims like 'alcohol free' are potentially mis-leading and not always correct. But we all know what we are talking about here so let's get back to Ethanol or what the average person would call alcohol.

Alcohol and the skin - Let's start by looking at what it does on the inside.

Like with so many articles that I write I started off my research with a strong sense that alcohol is damaging to the skin in high concentrations, it feels like it should be based on what I have heard and what it feels like when applied - fresh, drying, cold etc. While a researcher has to have an idea of what they are trying to find out (or else you would never know what to type into your Google Scholar search engine) human bias is always a risk factor in this situation. I think alcohol is bad for the skin so I Google things like 'what damage does alcohol do to the skin' or 'how damaging is alcohol to the skin'. Being human that's exactly what I did first.

It wasn't hard to find a number of papers talking about the physiological skin changes experienced by people and animals that had been exposed to alcohol. I found studies that found links between severity of psoriasis and alcohol exposure. Studies that found the skin to become increasingly dry, itchy and red following alcohol exposure and a weakening in the skins barrier function linked to alcohol. Alcohol abuse has also been linked to discoid eczema, superficial infections and delayed wound healing. But before we all run a mile from that alcoholic toner it is well worth knowing that these studies were linked to the ingestion of alcohol and not its topical application. Further, there is some discussion around whether the metabolism of alcohol, which breaks ethanol down to acetaldehyde, is part of the problem - that it could be the acetaldehyde that is having the most negative effects on epidermal tissue. Food (or drink) for thought. I doubt I'd get many takers if I told people that their skincare brand would be safer and get better dermatological results if it marketed its self as supporting sobriety rather than focusing on its formulations being alcohol free.

But you would think that if alcohol were so terrible on the inside it would be just as bad on the outside? When applied topically.

Time after time this has been found not to be the case, that alcohol ISN'T damaging the skin. In fact, studies carried out on health professionals that have to wash and/ or sanitizer their hands several times an hour during their shift were found to fair better in maintaining their skins barrier function when 'washing' with an alcoholic hand sanitizer vs. a soap based wash alone or soap plus alcohol sanitizer step. Now I know that soap comes in many shapes and sizes but when lumped all together as 'surfactants' the scientific evidence is swaying to alcohol being the milder option vs. surfactant based cleansers. How many brands would ditch their soap and body wash in favour of an alcoholic body drench? Not many I bet.

But we must dig a little deeper here because as a scientist I know that alcohol does something to the skin and it would be helpful to know what and how.

Chemically speaking alcohol is a good solvent and by that I mean it can grab hold of other chemicals (maybe anti-ageing actives, phytochemicals (plant based actives), antioxidants or vitamins for example) and push them deeper into the skin. Alcohol has been studied extensively by pharmacists looking for ways to improve trans-dermal drug delivery and reduce our reliance on needles. It is here we need to look for some answers as to what alcohol actually does to the skin.

It is safe to say that alcohol's mechanism of action as a drug delivery agent has taken a fair while to work out. Initial investigations seemed to point to alcohol disrupting the skin barrier function - something that is far from ideal, especially if the effects are cumulative and/or last a long time. Basically if a chemical disrupts the skin barrier it can leave it vulnerable to infection and generally weak. Things like cortisone if used over a long period of time can permanently reduce barrier function, which is why that particular drug is strictly regulated.

But alcohol wasn't found to act that way.

Alcohol was found to act as a solvent on the skin, a solvent capable of dissolving some of the lipids (fats) that make up the skin barrier. This lipid removal service enables the passage of some actives across the skin barrier and enhances skin penetration. As simple as that sounds skin penetration isn't quite so neat. The active that is to be delivered has to favour the skin over the ethanol or else you get left with a concentrated dose of active on the outside of the skin which can cause irritation and skew results.It is likely that some of the irritation seen in alcohol solvent based transdermal preparations have more to do with the active concentration increasing over time than the alcohol its self but that's an area of ongoing research.

But doesn't alcohol dry the skin out?

This is another area where there are still some questions. A number of studies have found that Trans Epidermal Water Loss figures rise after skin is treated with ethanol - basically the skin loses more water. Other studies found no increase in water loss. I feel it is logical that if the skins barrier has been disrupted albeit temporarily by the loss of lipids it could lose more water than normal but what would matter here is whether the skin could fully recover and if so how quickly. Time and time again studies looking at how the skin fairs after alcohol saturation have found the skin to be un-irritated and intact would point to these changes in water loss being minor in all but the most sensitive of skin cases. Put simply it is likely that our skin can tolerate and correct for this just as it would tolerate and correct for a windy day, a bit of extra sweating or a cold snap.

A bit more good news about topically applied alcohol.

On the plus side at least one study has found that the topical application of 10% ethanol stimulates cell regeneration and speeds up wound healing - quite useful in some situations, especially when you want to recover quickly from those drunken falls!

OK, so what about how the skin metabolizes alcohol - is there a risk of irritation from any acetaldehyde that is produced, like we found inside the body?

While it is true that alcohol is metabolized to acetaldehyde by the skin the concentration of acetaldehyde found in skin regularly exposed to alcohol via hand washes and the like were found to be below acute toxic levels during trials. The only exception to this was with children and especially children applying alcoholic solutions to open wounds on a regular and ongoing basis. Quite simply the amount of alcohol that makes its way deep enough into the skin to be metabolized even with regular use of an alcoholic product (60% plus ethanol content) is minimal compared to the acetaldehyde levels that would be found in the skin of someone who drinks alcohol regularly.

So the bottom line is that yes, there is a small risk of irritation because of this but it is practically insignificant in relatively healthy adults.

So is it 'bottoms up' for alcohol or should we all stay sober?

After evaluating all of the evidence it looks increasingly likely that topically applied alcohol in the manor that the average cosmetic user is exposed to it - in a spritzer; perfume; some moisturizers or tinctures - poses absolutely no threat to the health and vitality of the skin. In fact I can see several benefits in adding a bit of alcohol to a cosmetic product:

• Alcohol has been found to enhance skin penetration of several actives through the skin. It doesn’t work in all situations but when it does work it works well.
• Alcohol is considered to be a gentler alternative to soap based hand washes and a preferred way of sanitizing hands for medical professionals.
• Alcohol can help to clean up wounds and speed up healing but applying alcohol to open wounds will sting and will increase skin penetration of alcohol which may result in a little topical irritation due to the acetaldehyde metabolite.
• Alcohol can make skin creams feel lighter and more refreshing - great in hot and humid climates.
• Alcohol can make perfumes spray better and smell better.
• Alcohol is refreshing in a skin toner
• Alcohol can help to preserve your cosmetic product by reducing the amount of free water.
• Alcohol can help to make spritz formulations crystal clear by improving the solubility of the essential oil or fragrance.
• Alcohol is natural and can be made from waste plant material - how good is that!

So I say use it - it's one of natures' goodies as long as you don't abuse it.

And could we get drunk if we bathed in vodka?

Probably not is the answer to that! A study of five people, four children and one adult who were asked to wear a leg bandage soaked with 200ml of 95% ethanol for 4-9 hours were found to have no blood alcohol reading at the end of the trial. 200ml of 95% ethanol is equivalent to 16 shots of 40% proof spirit.

Amanda Foxon-Hill